Help - 2 non working Chinese folding electric bikes

[Dave Edwards]

I have 3 x GB22 electric bikes bought through a retailer in Belgium. They are manufactured by the Guangzhou Yutu Electric Bike Company in China and supplied to me by an online retailer. They are folding 22inch wheel bikes with the battery housed in the frame. They are pedal assist or battery only. I live in the uk and have an identical problem with 2 of them. When I try and ride them they cut out at about 5 km/h and will not start again until I have disconnected the battery and them reconnect it. I have swapped the battery, control unit in the frame and also the contacts with the good bike and still get the same problem. If I lift the back wheel off the ground the bike runs ok but as soon as i put any load on it I get the problem. I can only assume that the hub motor is the problem but cannot see any easy way to swap it with good bike to prove this. Is there a my way there is a cutout in the rear wheel hub/motor that could cause the problem or can you advise on any remedy. The supplier is reluctant to help and because they are in Belgium I cannot go and see them.
HELP. Thanks for any advise. Dave.

 

[Deleted member 4366]

It's almost certainly the battery that is causing the problem. The BMS (battery management system) is cutting off either because of over-current (not so likely) or under-voltage (very likely). Are you sure you charged the battery properly? Measure the voltage at the terminals with a voltmeter and post the results here.

 

[Dave Edwards]

It's almost certainly the battery that is causing the problem. The BMS (battery management system) is cutting off either because of over-current (not so likely) or under-voltage (very likely). Are you sure you charged the battery properly? Measure the voltage at the terminals with a voltmeter and post the results here.

Hi, thanks for your reply. As I said I have 3 of these bikes one of which works perfectly. I have swapped the battery from this good bike to the bikes that are faulty and this does not help the problem. I have also put the battery from the faulty bike on the good bike and it works fine. I feel that this must rule out the battery. I have also swapped the silver box full of electronics from the good bike to the faulty ones and still no joy. Unless the BMS is not housed in the silver electronic box then it seems it cannot be this. However would the BMS be housed in the rear wheel motor hub as this is the only thing I have not managed to to swap and prove. Cheers. Look forward to your reply. Dave

 

[trex]

it seems that you have ruled out the battery and controller. The next item to check is the LED display. This unit talks to the controller - telling the controller when to switch the motor and how to set the assistance level. It looks like this unit may have a communication fault. If you can connect the LED display on the good bike to the controller on the bad bike then it's orth a try.

Good luck.

 

[Dave Edwards]

Hi

it seems that you have ruled out the battery and controller. The next item to check is the LED display. This unit talks to the controller - telling the controller when to switch the motor and how to set the assistance level. It looks like this unit may have a communication fault. If you can connect the LED display on the good bike to the controller on the bad bike then it's orth a try.

Good luck.

, I am back home with the bikes Tuesday and will see if I can swap the LED display to prove this. This is all part of the throttle on the handle bar. Thanks for your help and will let you know how I get on. Cheers. Dave

 

[Deleted member 4366]

There's not really anything in the motor that could cause that problem. If there was anything wrong with the motor, it wouldn't run at all.

I agree that the batteries are OK, so the problem must be a bad connection somewhere unless you have a LCD or LED display, or an external switch that switches off the battery. How do you switch the bike on?

Edit: I've just seen the key-lock hanging underneath the frame. I suggest that you check the wiring to it very carefully. Check the solder joints. You often get dry joints on other key-switches. If you can, temporarily wire it out of the circuit to eliminate it as the cause.

 

[Dave Edwards]

There's not really anything in the motor that could cause that problem. If there was anything wrong with the motor, it wouldn't run at all.

I agree that the batteries are OK, so the problem must be a bad connection somewhere unless you have a LCD or LED display, or an external switch that switches off the battery. How do you switch the bike on?

Edit: I've just seen the key-lock hanging underneath the frame. I suggest that you check the wiring to it very carefully. Check the solder joints. You often get dry joints on other key-switches. If you can, temporarily wire it out of the circuit to eliminate it as the cause.

The bike is switched on by a key on the led display/throttle on the handle bar. The key underneath the frame locks the battery inside the frame so it cannot be stolen. What throws me is that every time I disconnect and then reconnect the battery it seems to reset itself and runs till I put it under load. It seems my best bet is to swap the led display/throttle for the one that I know works and see what happens. Cheers. Dave.

 

[Deleted member 4366]

There's three ways of switching. The most common way is with a large key-switch on the battery or very close to it. Next is a switch on the battery supply to the controller. With this method, the main power to the motors (thick red and black wires) is always on, but blocked by the controller. It branches inside the controller to make a separate line that powers the controller. The switch is on that branch, which only uses a few watts, so the switch only needs thin wires. The switch can be part of a LCD or LED display or a separate switch when that branch is brought out of the controller and back again. I guess that's what you have. The third method is a switch to the BMS, which will cause the BMS to block power output.

Assuming the first or second second type: If you can identify the two wires to the throttle switch, you can temporarily short them at the controller end. They're possibly thin red and orange wires or a single thin red coming out of the controller, and maybe green and yellow on the throttle cable. If you can show me a picture or describe the connectors on the throttle cable, I should be able to identify them.

Your symptoms are consistent with the power supply being interrupted as the current increases, which would mean a connection breaking down under load. You should check all the connections and solder joints between the battery and the controller. The type 2 switch above would be unlikely to break down under load. If it were faulty, it would be more likely to cut out on a bump, but you should bypass it anyway just to make sure. If it's a type 1 switch, it's a prime candidate.

 

[Cyclezee]

I have 3 x GB22 electric bikes bought through a retailer in Belgium. They are manufactured by the Guangzhou Yutu Electric Bike Company in China and supplied to me by an online retailer. They are folding 22inch wheel bikes with the battery housed in the frame. They are pedal assist or battery only. I live in the uk and have an identical problem with 2 of them. When I try and ride them they cut out at about 5 km/h and will not start again until I have disconnected the battery and them reconnect it. I have swapped the battery, control unit in the frame and also the contacts with the good bike and still get the same problem. If I lift the back wheel off the ground the bike runs ok but as soon as i put any load on it I get the problem. I can only assume that the hub motor is the problem but cannot see any easy way to swap it with good bike to prove this. Is there a my way there is a cutout in the rear wheel hub/motor that could cause the problem or can you advise on any remedy. The supplier is reluctant to help and because they are in Belgium I cannot go and see them.
HELP. Thanks for any advise. Dave.

Hi Dave,

When you say that one is working perfectly, do you mean in pedelec and ebikes modes and how does it perform?
Ignoring the fact that the bikes were manufactured in China, in mainland EU, where you sourced the bikes from, throttle or ebike mode, by law the throttle should only assist to 6 Km/h or walking pace, but in pedelec mode they should assist up to a limit of 25 Km/h.

There could be an issue with the settings of the handle bar display.

For 1 of 3 identical bikes to work perfectly and the other 2 not is odd.

 

[Cyclezee]

Hi Dave,

When you say that one is working perfectly, do you mean in pedelec and ebikes modes and how does it perform?
Ignoring the fact that the bikes were manufactured in China, in mainland EU, where you sourced the bikes from, throttle or ebike mode, by law the throttle should only assist to 6 Km/h or walking pace, but in pedelec mode they should assist up to a limit of 25 Km/h.

There could be an issue with the settings of the handle bar display.

For 1 of 3 identical bikes to work perfectly and the other 2 not is odd.

I assume this is the bike in question http://www.greenbike.us/gb22.html

 

[RobF]

There's three ways of switching. The most common way is with a large key-switch on the battery or very close to it. Next is a switch on the battery supply to the controller. With this method, the main power to the motors (thick red and black wires) is always on, but blocked by the controller. It branches inside the controller to make a separate line that powers the controller. The switch is on that branch, which only uses a few watts, so the switch only needs thin wires. The switch can be part of a LCD or LED display or a separate switch when that branch is brought out of the controller and back again. I guess that's what you have. The third method is a switch to the BMS, which will cause the BMS to block power output.

Assuming the first or second second type: If you can identify the two wires to the throttle switch, you can temporarily short them at the controller end. They're possibly thin red and orange wires or a single thin red coming out of the controller, and maybe green and yellow on the throttle cable. If you can show me a picture or describe the connectors on the throttle cable, I should be able to identify them.

Your symptoms are consistent with the power supply being interrupted as the current increases, which would mean a connection breaking down under load. You should check all the connections and solder joints between the battery and the controller. The type 2 switch above would be unlikely to break down under load. If it were faulty, it would be more likely to cut out on a bump, but you should bypass it anyway just to make sure. If it's a type 1 switch, it's a prime candidate.

http://www.pedelecs.co.uk/forum/threads/still-think-chinese-ebikes-are-crappy.17486/

!

 

[Dave Edwards]

Well

http://www.pedelecs.co.uk/forum/threads/still-think-chinese-ebikes-are-crappy.17486/

!

Hi, thanks to those who have been helping me. I am lucky that out of the three bikes I have one works perfectly. To recap I have swapped with the good bike, the battery, the plate that connects with the battery. The silver box in the frame that has all the electronics in it and now the switch/throttle/LED display on the handle bar complete with the loom back to the silver box in the frame. None of these has changed the fact that the bike cuts out as soon as the motor comes under load either on the throttle or peddle assist. I did also disconnect the sensor on the crank cog but this did not change any thing. Apart from the rear wheel and the motor on its hub I have now swapped everything to no avail. I know there are those out there who are thinking you get what you pay for and #^¥$€+ Chinese bikes but despit that I have three which it looks like I am stuck with. So any more suggestions. Do any of you knowledgable folks live anywhere near Ely, Cambridge. Happy to pay you for your time if I can visit you for some direct help. Cheers. Dave.

 

[trex]

then the next logical step is swapping the motor wheel.

 

[Deleted member 4366]

You could send one to me in Telford, but it costs £35 each way for an Ebike with Paisley freight. You might get away with £25 if you say it's a bicycle. I doubt that they'll know. I sent a folding electric bike with them for £25. Send me a PM if interested. No charge for fixing it.

You could double check the motor connections. Make sure that they're tight and fully home..